Forty unsymmetric N-phenyl-N'-pyrimidylurea derivatives were synthesized in moderate-to-good yields by one-pot reductive carbonylation of nitroaromatics using selenium or selenium dioxide as the catalyst, aminopyrimidine derivatives as co-reagents, and carbon monoxide as the carbonyl source. The reaction parameters were investigated, as was the reusability of the catalysts. We found that selenium- or selenium dioxide-catalyzed reductive carbonylation of the nitroaromatics exhibited reaction-controlled phase-transfer phenomena of the catalysts. (C) Wiley-VCH Verlag GmbH Co.